Vulcanization accelerator and process of making same



25 canization accelerators.

Patented Apr, 12, 192? I UNITED STATE HABOLD WALTER ELLEY AND DONALD HOWARD POWERS, OF WILMINGTON, DELA- WARE, ASSIGNORS TO 1!. I. DU PONT DE NEMOUBS & COMP, OF W i a DELAWARE, A CORPORATION OF DELAWARE.

VULCANIZATION ACCELERATOR AND PROCESS OF I IEAKING SE.

No Drawing. Application filed December The simplest saturated member of this class of substances would have the following structural formula:

H/ \OH:

which may be designated hydraz'iminomethane.

The members of this class in which we are at present more particularl interested are those which possess radica s which render the substances, or certain of their decomposition products, valuable as rubber-vul- Some of the members of said class of substances having this property of accelerating vulcanization are characterized by having most probably the following atomic grouping:

where R,, R R and R are organic radicals, and R is a divalent organic radical. Those members which we have so far found (CBdzNO-NO-H Ring 2, 1924'. Serial No. 758,524.

most useful as accelerators have the followmg general, incomplete, structural formula:

or am 1; R and R stand for alkyl or aryl radica and R stands for hydrogen or an organic radical. Substances of this type may be produced in general by first condensmg one molecular proportion of a nitrosodialkyl- (or diaryl-) aniline with two mo lecular proportion of a primary amine to produce a compound having most probably the formula and then condensing this product with a J compound containing a reactive methylene group.

For example when para-nitroso-dimethylaniline is condensed with two equivalents of aniline, a product is obtained'which reacts vigorously with formaldehyde to give a condensation product which shows remarkably high curing power, su erior to a cure obtained from nitrosoimethylaniline condensed with formaldeh de, aniline condensed with formaldehy e, or a mixture of these roducts. isprobably as follows: i

The course'of this reaction 1 The formation of this product is by no means limited to this method of preparation; for example it may also be prepared a es awe by treating nitroso-dimethylaniline with methylene-dianilide or a mechanical mixture of the two.

The condensation; product of nitroso di I methylaniline, toluidine, and formaldehyde has been found to have extremely high 'cur ing ,owers. This product maybeprepared in t e following manner. 1 Four hundred and seventy-two pounds of ortho-toluidine are heated to 275 F. and three hundred and nine pounds of para-nitro'so dimethylaniline are slowly run in while the mixture is vigorously agitated. About fifteen minutes after the .nitroso-dime'thyaniline has been added, concentrated aqueous --formaldehyde solu- .c tion I weighing approximately two hundred pounds'is runinL' Atthe end. 0

f an hour the mix is run ofiand driedat 260 F;

steam pressures; In producingvthe new substances thereagentwhich isYTto: becondensed with, the nitroso-compound? may be practically any primary amine, forexample methyh, ethyl-5" the formation of the. hydrazimin-omet ring, there may be used, in place offormaldehyde, other reactive methylenewontaining compounds such as thepolymeric forms of formaldehyde for example, para'fomnaldehyde), the aldehyde'ammonias, hexamethylene-tetramine, and methylene-dichloride? d th re ion reactiv -meth le e-co v an 8 exp SS 8 y n n 5J-A composition comprising a substance taining compound is also used to include the aldehydes. in general such as acetaldehyde, butyraldehyde, benzaldehyde, iurfu' raldehyde, etc, as well as the 'allrylidenedihalides (for example, butylidene dibrm a When tested in theofollowing mixture. a tensile strength, of three thousand three hundred andslxty pounds was obtained with anyelone g'ation of eightchundred andthirty per cent amine (for'example, aniline or Q tolnidine) with one molecular equivalentjofi para-nitroso-dimethylaniline, followedbycon'densazation' of rubbenbut it is not asvaluable f in this respect as when the acetaldehyde is; replaced by formaldehyde; This latter product on :the: other: hand isygfound to 'sbe methylaniline with "an ali hatic primary amine, such as butyl-amine, gillowed by condensation of the resulting product with an aliphatic aldehyde such as formaldehyde. We claim:

inferior in accelerating power-tofa product a obtained by condensation of para-nitroso-di- '1. A composition,comprising-a'hydraziminomethane compound. t I

2., A composition comprising a substance whose molecules contain the following:

heterocyclic ring:

whoeei molecules where-fl represented a:divalent jlorgauic -i '-a'.- A; composition comprising a" substance propyl-, butyle; .benzyl phenyl-, or-tolyb', amine. For the last reaction, to .comglete ane {whose molecules contain the following atomic g grougoing r whose molecules contain the following atomic grouping:

where R l 5R5 and R represent alkyl radicals.

i a Mama-a.amass mama 1 contai f HQ Dg 6. A composition comprising a substance whose molecuies con ain The following atomic grouping:

where R R and R,, represent organic radicals.

7 A composition comprising a substance obtainable by condensing one molecular proportion of a nitroso-dialkylaniline with two 1 molecular proportions of a primary amine,

and condensing the resulting product with one molecular proportion of a compound containing a reactive-methylene group, the

molecules of said substance having most probably the following graphical formula:

. Ra 1 R1 N where R, and R represent alkyl radicals, R and R replresent organic radicals, and R stands for ydrogen or an organic radi- V cal.

10. A composition comprising rubber mixed with a substance whose molecules contain the following heterocyclic ring: I

11. A composition as defined inclaim 3 which includes rubber mixed with said'sulr stance. I I

12. A composition as defined in claim 4 which includes rubber mixed with the sub stnnce described in said claim. 1

13. A com osition as defined in claim 5 which inclu es rubber as. the major component thereof. e

14.- Vulcanized rubber derived from rubber combined with a vul'canizing agent and a substance whose molecules contain the atemic grouping: a

ical.

ber combined with a vulcanizing agent and a substance -'whose molecules contain the atomic grouping: p a

16. Vulcanized rubber, derived from rub- ,ber combined with a vlucanizing agent and a substance whose molecules contain the atomic grouping:

R w H1 V R/ N I where R R,, R,, and. R represent organic radicals. v

17. Vulcanized rubber d rived from rubber combined with a vulcanizing agent and a substance whose molecules contain the atomic grouping: 1

R .4 I v, where 3,, R R and R, represent alkyl radicals.

18. The process of treatin rubber which comprises combining with ru her a vulcfanizing agent anda hydraziminomethane compound, and vulcanizing the rubber. w

19. The process of treatin rubber which comprises mixing with. the ru her a vulcauiz i densing a nitroso-dialkyl-amino compound f. with a primary amine and condensing the resuiting amino-hydrazine derivative withare 7 m5 active aldehyde, and subjecting the mixture thus formed tovulcanization. I

20. The process of treatin rubber which comprises mixing with the ru her a vulcanizcomprises mixing with thie rubber a vulcanizing agent and the organic compound re sulting from the action of a reactive" aide hyde on the condensation product of a paranitroso-dialkylaniline and a primary he, and vulcanizingithe mixture.

22. The process of preparing'an accelera tor which comprises combining two molecular proportions of aprimary amine with one molecular proportion of a nitroso-disub stituted-amino. compound, and treating the resulting product with a substa where R represents a divalent organic. rad

nee containing a reactive methylene up.

23. The process of pre aring an acelerator which comprises com ining two molecular-proportions of a primary amine with ing agent and the product obtainable by'com c f one molecular proportion (if a nitroso-disubstituted-amino compound, and treating t the resulting product with a reactive aldehyde.

24. The process of preparing an acceleratOr which comprises combining two molecular proportions of a primary amine with one molecular proportion of a nitroso-disubstituted-amino compound, and treating the resultin product with formaldehyde.

25. The process of preparing an accelerator which comprises combining two molecular proportions of a primary amine with one molecular proportion of a para-nitrosodialkylaniline to form an amino-hydrazine derivative, and condensing the latter with a reactive aldehyde.

26. The process of preparing an accelerator which comprises combining two molecular proportions of an aliphatic primary amine with one molecular proportion of a nitroso-dialkylaniline to form an amino-hydrazine derivative, and condensing the latter with a compound containing a reactivemethylene group.

27. A process as defined in claim 26 in which the amino-hydrazine derivative is condensed with a reactive aldehyde.

28. A process as defined in claim 26 in which the amino-hydrazine derivative is condensed with formaldehyde.

29. Vulcanized rubber obtainable by subjecting to a vulcanization temperature and pressure a rubber mix comprising rubber,

sul hur, zinc oxide and an accelerator Whose mo ecules contain the following atonnc grouping:

In testimony whereof We afiix our signacures.-

HAROLD WALTER ELLEY. DONALD HOWARD POWERS 

